Managing Intelligent Multicasting (Layer 2 & Layer 3)
a client of) a multicast session. Router ports are ports that are attached to (or in the path to) multicast routers and must be treated specially. All multicast traffic on a VLAN must be forwarded to the router.
You can manually create and delete multicast sessions through the user configuration. The addition of client and router ports can also be performed manually. Dynamic intelligent multicasting is achieved through IGMP snooping, LGMP (Lucent Group Membership Protocol), or CGMP (Cisco Group Management Protocol) snooping. All of these mechanisms are based on the assumption that the client host is running IGMP, requesting membership in the IP multicast session.
Note: If there is no multicast session created for a multicast flow in a VLAN, then that multicast flow will be flooded to all ports on the VLAN. Intelligent multicasting must be enabled for any dynamic intelligent multicasting to be active.
Layer 3 Dynamic Intelligent MulticastingIGMP snooping is supported for VLANs that have IGMP interfaces enabled. This is the recommended means of supporting dynamic intelligent multicasting in Layer 3. For all VLANs that do not have an IGMP interface enabled, the Layer 2 dynamic intelligent multicasting mechanisms (LGMP client and CGMP snooping) are supported.
Note: For Layer 2 or Layer 3 LGMP to perform properly, VLAN IDs must match between switches. Specifically, if two switches are connected with a
IGMP snooping is only supported in Layer 3. As IGMP reports are received by the switch, IGMP sessions are created. Intelligent multicast sessions are created and the ports on which these reports are received are added to the appropriate sessions. When the IGMP session is terminated, the associated intelligent multicast session is deleted.
Note: IGMP snooping is only available for VLANs that have an IGMP interface enabled.
Cajun P550/P220 Switch Operation Guide |